Automatic web tension control

ABSTRACT

The web tension device includes a tension producer and tension sensor interconnected with controls. The tension sensor consists of a member loaded in one direction by a load cell and in the opposite direction by the tensed web. The position of the member is sensed by air escaping through a nozzle controlled by a &#39;&#39;&#39;&#39;flapper&#39;&#39;&#39;&#39; in a sensor arm. A plurality of bars actuated by an air cylinder produce the tension on the web through the interconnected controls. The control system utilizes air pressure supplied to the load cell through an orifice to an air relay and the sensor nozzle. Pressure not escaping from the nozzle is amplified in the relay which supplies air to the tension producing cylinder in the tension producer.

United States Patent [191 Rowe [ 1 Oct. 16, 1973 AUTOMATIC WEB TENSIONCONTROL [76] Inventor: E. Riley Rowe, Hartsville, S.C. [22] Filed: Apr.12, 1971 [21] Appl. No.: 133,066

[52] U.S. Cl 226/39, 226/44, 226/45, 226/114 [51] Int. Cl B65h 25/04[58] Field of Search 226/39, 44, 45, 113, 226/1 14 [56] References CitedUNITED STATES PATENTS 1,941,597 1/1934 Cavagnaro 226/114 3,032,245 I5/1962 George 226/39 3,460,729 8/1969 Treff 226/44 PrimaryExaminer-Richard A. Schacher Attorney-C. Gordon McBride [57] ABSTRACTThe web tension device includes a tension producer and tension sensorinterconnected with controls. The tension sensor consists of a memberloaded in one direction by a load cell and in the opposite direction bythe tensed web. The position of the member is sensed by air escapingthrough a nozzle controlled by a flapper in a sensor arm. A plurality ofbars actuated by an air cylinder produce the tension on the web throughthe interconnected controls. The control system utilizes air pressuresupplied to the load cell through an orifice to an air relay and thesensor nozzle. Pressure not escaping from the nozzle is amplified in therelay which supplies air to the tension producing cylinder in thetension producer.

9 Claims, 6 Drawing Figures IO L 5 O 46 l is I8, \v E n \se/ 58 i-= 9g20 I 4 92 64 i if 9" l k of! v 28 6O \\Y2\26 26 32 62 4 PAIENIEDHCI 16m3 SHEET E OF 3 FIG. 4

INVENTOR.

E. RILEY ROWE c G R o g: RIDE ATTOfifi ,PATENIEDUBHSIHH I 3.765.584

- s m as? 3 INVENTOR. .E. RILEY" ROWE BY 0 GORDQN MoBRlDE 1 AUTOMATICWEB TENSION CONTROL In the manufacture of various items in which a webis passed through some point at which it is wound or its direction ischanged, there are various forces which cause breakage or an undesiredtension or change of direction of the web. This is especially true inthe manufacture of spiral tubes wherein a web of paper or fi-.

brous material is wound about a mandrel to produce a tubular article.Any requirement for the winding of a linearly moving web would have thesame difficulty in that various constant, preset tensions and pressuresare desired to insure proper control of the web. Various devices havebeen utilized in the past to accomplish control of webs and in mostcases these devices have been large and cumbersome. Moreover, thesedevices do not operate automatically and it is necessary to have askilled operator readily available for any alteration in conditions.

In the production of tubular members from paper webs there has also beena problem in accomplishing the proper tension on the web being woundabout the mandrel to insure the proper application and sticking of theplies of material. Various devices that have been utilized for applyingtension to control the amount of adhesive applied to the web have beenexpensive and cumbersome and of a complex construction not easilyunderstood by the average operator of a spiral machine.

The above disadvantages are overcome by the instant invention wherein itis an object to provide a web tension control device which will reduceply or web breakage and improve the bond between plies in a tubularconstruction. 7

It is another object to improve diameter control of tubular articles andply gap control by utilization ofa novel web tension control device.

Still another object of the instnat invention is to provide a device forautomatically tensioning a moving web of material to any desired, presettension.

Another object of the instant invention is to provide an automatic webtension control device which is of simple and compact construction andeasily operated.

A further object of the instant invention is to provide a deviceutilizing a tension producer with a tension sensor andconnectingcontrols for coordinate operation of each. i

It is still another object of the instant invention to provide anautomatic web tension control device utilizing a pneumatic system forsensing the tension on a web and applying a mechanical pressure toestablish the desired tension in the web automatically.

Yet another object of the instant invention is to provide a tensionsensor having a memberloaded in one direction by a load cell and in theopposite direction by the web to be tensed and utilizing pneumaticpressure escaping through a nozzle against a sensor arm to actuate thetension producer and automatically insure the proper tension on the web.

The above objects and advantages are accomplished by utilizing apneumatic pressure sensor which operates on the web to determine thetension thereon and conveys a signal corresponding to the pressureescaping from the nozzle as caused by a rod sensor through controlswhich activate an air cylinder positioner for movement of a plurality ofco-acting, oppositely disposed bars. The web is fed through these barswhich exert a pressure on the web in relation to their angulardisplacement to one another.

Reference is now made to the drawings wherein like numerals refer to thesame or similar parts and wherein the invention may be best understoodby reference to the following description taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a side elevational view, with portions omitted for clarity, ofthe device of the instant invention;

FIG. 2 is an enlarged side view of a portion of the device as shown inFIG. 1;

FIG. 3 is a side elevational view, with portions omitted for clarity,taken from the reverse side of the device of the instant invention fromthat shown in FIG. 1;

FIG. 4 is an end view of the device of the instant invention taken fromthe left of FIG. 1;

FIG. 5 is a schematic diagram of the pneumatic system and controls for;and instant invention.

FIG. 6 shows a partial view of a schematic diagram of an alternativeembodiment of the system and controls shown in FIG. 5.

Referring now to the drawings and more particularly to FIG. 1 whereinthe novel automatic web tension control apparatus 10 is shown to includesensor assembly 12 interconnected with actuator 16 by control system 14.Tension production assembly 18 accomplishes the actual tensioning of web20.

The web tension control apparatus 10 may be mounted in the system forassembly of a spiral tube or in a position such that web 20 will runlongitudinally therethrough. Tension control device 10 may be mountedfrom any foundation or support available and generally utilizes amounting such as bracket 22 through which rods 24 extend to support thetension control device 10 from below. Side bars 26 are mounted andinterconnected by guide 28 at one end and similar structure at theopposite end. Thus it is seen that a framework is established with sideplates 26 forming the sides and which supports sub-assembly 12, controlsystem 14, actuator 16 and tension producing assembly 18.

Tension producing assembly 18 is comprised of a plurality of operatingarms 30 which are pivotally mounted over friction bars 32 extendingbetween side plates 26 and which are connected to operating lever 34 bypivot 36. Movable friction bars 38 are mounted above and to the right,as seen in FIG. 1, of the fixed friction bars32. Because operating arms30 are pivoted about fixed friction bars 32 and pivots 36 on operatinglever 34, it is readily seen that a horizontal movement of lever 34 inthe direction of travel of the web will effect an angular movement ofmovable friction bars 38 with regard to fixed friction bars 32. It isobserved that web-20 passes over guide 28 and between each of the pairsof friction bars which is comprised of a fixed friction bar 32 and amovable friction bar 38. Thus as operating lever 34 moves to the rightand causes movable friction bars 38 to move in an angularly downwarddirection a greater tension is applied to web 20 and less tension isapplied as operating lever 34 moves to the left and rotates movable bars38 upwardly and out of hard contact with web 20.

Lever 34 is connected to actuator 16 by pivot link 40 which pivots abouta fixed friction bar 32 and cylinder rod 42 such that actuation of aircylinder 16 effects the horizontal movement of operating lever 34.Actuator 16 is of conventional construction having a diaphragm typecylinder for minimizing friction. This apparatus permits pressureexerted on one side of the diaphragm to effect movement of rod 42 andthe attendant operating lever 34. Cylinder 16 is suspended fromframework 44 which includes uprights 46 and cross bar 48. Cross bar 48supports mounting rod 50 and spacer 52 upon which bracket 54' may pivot.Bracket 54 is rigidly attached to actuator 16 such that operation ofcylinder 16 and an elongation of cylinder rod 42 will permit rotation oflink 40 about fixed friction bar 32 and permit rotation of actuator 16in order to cause movement of operating lever 34.

Actuator cylinder 16 has pneumatic fitting 56 interconnected withactuator pressure gauge 58.

Sensor assembly 12 is also mounted from side bars 26 and includesstationary bars 60 across which web 20 passes. Rod sensor pivot 62extends across tension control device 10 and functions as a pivot forsensor arm 64. Sensor arm 64 has a pivot portion 66 which interconnectswith rod sensor pivot 62 and sensor bar 68. Sensor portion 70 of sensorarm 64 extends forwardly and has pneumatic reflector plate 72 mounted onthe lower edge 74 thereof for a purpose to be more fully understoodhereinafter.

Sensor nozzle 80 is interconnected by pneumatic line 82 to relay 84which forms part of control system 14.

Load cell 90 functions to provide a designated force against sensor arm64 through rod 92 such that there is a given load on sensor bar 68 and adifferential can be established. Load cell 90 is of conventionalconstruction and is connected by pneumatic line 94 to pressure gauge 96which is connected to regulator 122 that is capable, in one embodiment,of maintaining a pressure of to 30 psi. Load cell 90 is supported bysupport 98 and mount 100 which attach to side plates 26 and upright 46of framework 44, respectively.

Reference may now be had to FIG. wherein a diagram of control system 14is shown. It is seen that source of pneumatic pressure 110 provides theair passing through conduit 112 to filter 114 and through conduit 116 toregulator 118 for insuring a uniform pressure as required in each giveninstance. A pneumatic line 120 connects regulator 118 to regulator 122which in turn is connected to load cell 90 and gauge 96 by conduit 124.Conduit 120 has a branch 126 which connects regulator 118 to pneumaticrelay 84. It is noted that conduit 82 connects relay 84 with sensornozzle 80. As seen in the schematic diagram of FIG. 5, a cross branch128 connects conduit 82 with branch 126 through fixed orifice 140.However, it is to be understood, as seen in FIGS. 3 and 6, branch 128with orifice 140 may connect conduits 82 and 124, see especially FIG. 6.

Conduit 130' connects relay 84 to valve 132 which is connected byconduit 134 to gauge 58 and actuator cylinder 16. The direction ofpneumatic flow can be observed by reference to the arrows in FIG. 5.

OPERATION The controller would be properly mounted through mounts 24such that the longitudinal direction bars 32 and 38, respectively, beingseparated, as seen in FIG. 1, by the opening of toggle valve 132.

Web 20 of a material such as paper would be fed over guide 28 andbetween the respective pairs of fixed friction bars 32 and movablefriction bars 38 to stationary bar 60. Web 20 then passes over sensorpivot 62 and under sensor bar 68. Web 20 extends beyond stationary bar60 and to the point of use or the winding operation. Once the web hasbeen fed through the controller 10 as noted, regulator 122 is graduallyreset to permit greater sensor pressure on the air passing to load cell90. As the pressure is increased through regulator 122 the pressureexerted by the load cell 90 on sensor arm 64 is increased. The pressurewhich escapes through nozzle will have an effect on the pressure of theair within conduit 82 and, therefore, the pressure within relay 84 whichsupplies and controls the air flowing to tension actuator 16.

The web tension is read by the movement of sensor bar 68 as web 20passes between pivot 62 and sensor bar 68 thereby causing sensor arm 64to be raised or lowered with the attendant reflector plate or flapper 72such that there will be an alteration of pressure being released throughnozzle 80. If the tension of the web is less than that required tobalance the load cell force which is being exerted downwardly from loadcell by rod 92 against sensor arm 64, the nozzle 80 is closed raisingthe back pressure in conduit 82 to effect a signal to relay 84. Thisincreases the pressure to actuator cylinder 16 which acts on operatinglever 34 to reset the movable friction bars 38 in reference to fixedfriction bars 32 and thus applies greater pressure for greater tensionuntil a balance is reached. The converse is also true and a greatertension causes reflector plate 72 and sensor arm 64 to raise permittinga greater flow of air from nozzle 80 and reducing the pressure inconduit 82 and relay 84. Thus, the air pressure to actuator cylinder 16is reduced and pivot arm 42 would be raised such that operating lever 34moves to the left, as seen in FIG. 1, effecting rotation of operatingarms 30 counterclockwise. This action raises movable friction bars 38upwardly to permit a less restrictive movement of web 20 between fixedfriction bars 32 and movable friction bars 38.

Although the specific structure of cooperating tension bars isdescribed, it is to be understood that tension in the web may beproduced by a compression or other device which is powered by a fluidactuator.

Thus it is seen that the instant invention permits a variabledesignation of the tension of a moving web as desired by the machineoperator. The operator can set the desired tension in the web and nothave to maintain a continual surveillance of the operation as the webtension control device 10 senses the web tension and automaticallyadjusts the friction to insure a constant tension regardless of theangular positioning of the web. Because web tension can be controlledaccurately there is substantial reduction of ply breakage and improvedsticking of the various plies of the tube. The constant tension permitsthe scraper bars to have accurate contact with the web and thus leave amore uniform film of adhesive and improves the wander characteristic ofthe ply, as well as improving tube diameter control. The novel tensioncontrol apparatus of the invention is capable of use with various otherequipment such as deckle grinders or skivers. The instant invention iseconomical in construction, requires minimal maintenance and there is norequirement for highly skilled personnel in the operation of the device.It is possible to rapidly rotate the friction bars and guides and guidesand other parts as well as alter the angular positioning of the controldevice across the mounting bars 24 and thereby permit rapid alterationof the positioning of the device.

What is claimed is:

1. A web tension control apparatus comprising sensor means fordetermining the tension on a moving web; tension producing means formodifying the tension on the web; said sensor means including a memberhaving a force applied in one direction by a load cell to counteract aforce applied to said loaded member in the direction opposite to that ofthe load cell by the moving web; sensor arm means for actuating saidtension producing means; nozzle means for directing pneumatic pressureagainst said sensor arm means to accomplish the actuation of the tensionproducing means; actuator means for activating said tension producingmeans; and control means interconnecting said actuator means and saidsensor means, whereby the tension on the web is sensed and pressure isautomatically applied to establish the desired tension in the web.

2. The web tension control apparatus of claim 1 wherein said tensionproducing means includes: a framework; at least one friction barsupported by said framework; an operating arm pivotally connected toeach said friction bar; an operating lever pivotally attached to each ofsaid operating arm; and at least one movable friction bar mounted oneach said operating arm, whereby movement of said operating levereffects rotation of said operating arm and effects lesser or greaterforce against the web by said movable friction bar and said fixedfriction bar.

3. The web tension control apparatus of claim 1 wherein said controlmeans comprises: load cell means; at least one variable regulator in afirst conduit for connecting a source of pneumatic pressure and saidcell means; a pneumatic relay; a conduit connecting said relay to saidfirst conduit; a second conduit connecting said relay to a valve andsaid valve to said actuator means; said cell means having a rod foroperation with said sensor means; nozzle means for directing pneumaticpressure against said sensor means and connected with said relay by athird conduit; and a fourth conduit interconnecting said third conduitand said second conduit and having a fixed orifice therein. 1

4. A web tension control apparatus comprising sensor means fordetermining the tension on a moving web; tension producing means formodifying the tension on the web; said tension producing means includinga framework; a plurality of friction bars supported by said framework;at least one operating arm pivotally connected to each said frictionbar; an operating lever pivotally attached to each of said operatingarms; movable friction bars mounted on said operating arms; actuatormeans for activating said tension producing means; and control meansinterconnecting said actuator means and said sensor means, wherebymovement of said operating lever effects rotation of said operating armsand effects lesser or greater force against the web by said movablefriction bars and said fixed friction bars.

5. A web tension control apparatus comprising sensor means fordetermining the tension on a moving web; said sensor means including aframework having at least one stationary bar across which the web maypass; sensor arm means pivotally mounted to said framework; said sensorarm having a sensor portion; a reflector plate mounted on said sensorportion; nozzle means for directing pneumatic pressure against saidreflector plate; tension producing means for modifying the tension onthe web; actuator means for activating said tension producing means; andcontrol means interconnecting said actuator means in said sensor means,whereby the tension on the web is sensed and pressure is automaticallyapplied to establish the desired tension in the web.

6. The web tension control apparatus of claim 5 wherein said controlmeans comprises: load cell means; at least two variable regulators in afirst conduit for connecting a source of pneumatic pressure and saidcell means; a pneumatic relay; a conduit connecting said relay to saidfirst conduit between said variable regulators; a second conduitconnecting said relay to a valve and said valve to said actuator means;said cell means having a rod for operation with said sensor means;nozzle means for directing pneumatic pressure against said sensor meansand connected with said relay by a third conduit; and a fourth conduitinterconnecting said third conduit and said second conduit and having afixed orifice therein.

7. The web tension control apparatus of claim 6 wherein said tensionproducing means includes: a framework; a plurality of friction barssupported by said framework; at least one operating arm pivotallyconnected to each said friction bar; an operating lever pivotallyattached to each of said operating arms; and movable friction barsmounted on said operating arms. whereby movement of said operating levereffects rotation of said operating arms and effects lesser or greaterforce against the web by said movable friction bars and said fixedfriction bars.

8. A web tension control apparatus comprising sensor means fordetermining the tension on a moving web; tension producing means formodifying the tension on the web; actuator means for activating saidtension producing means; control means interconnecting said actuatormeansand said sensor means; said control means including load cellmeans; at least one variable regulator in a first conduit for connectinga source of pneumatic pressure and said load cell means; a pneumaticrelay; a conduit connecting said relay to said first conduit; a secondconduit connecting said relay to a valve and said valve to said actuatormeans; said cell means having a rod for operation with said sensormeans; nozzle means for directing pneumatic pressure against said sensormeans and connected with said relay by a third conduit; and a fourthconduit interconnecting said third conduit and said second conduit andhaving a fixed orifice therein, whereby the tension on the web is sensedand pressure is automatically applied to establish the desired tensionin the web.

9. The web tension control apparatus of claim 8 wherein said fourthconduit with said fixed orifice therein connects the third conduitconnecting said nozzle means and said relay to said first conduitconnecting 7 said variable regulator with said cell means.

UNITED sTATEs PATENT OFFICE ERTIFTCATE OF CORRECTION Patent No. 3,765,58Dated: 7 October 16, 1973 E. Riley Rowe It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

In the title information Assignee: Sonoco Products Company,

Hartsville, S. C.

Columnl, line 38 "'instnat"' should appear "instant- Signed and sealedthis 21st day of May 197A.

v (SEAL) Attest: I c. MARSHALL DANN Commissioner of Patents EDX'IARD1-i.FLETCl-H2I-i,JR. Attesting Officer

1. A web tension control apparatus comprising sensor means fordetermining the tension on a moving web; tension producing means formodifying the tension on the web; said sensor means including a memberhaving a force applied in one direction by a load cell to counteract aforce applied to said loaded member in the direction opposite to that ofthe load cell by the moving web; sensor arm means for actuating saidtension producing means; nozzle means for directing pneumatic pressureagainst said sensor arm means to accomplish the actuation of the tensionproducing means; actuator means for activating said tension producingmeans; and control means interconnecting said actuator means and saidsensor means, whereby the tension on the web is sensed and pressure isautomatically applied to establish the desired tension in the web. 2.The web tension control apparatus of claIm 1 wherein said tensionproducing means includes: a framework; at least one friction barsupported by said framework; an operating arm pivotally connected toeach said friction bar; an operating lever pivotally attached to each ofsaid operating arm; and at least one movable friction bar mounted oneach said operating arm, whereby movement of said operating levereffects rotation of said operating arm and effects lesser or greaterforce against the web by said movable friction bar and said fixedfriction bar.
 3. The web tension control apparatus of claim 1 whereinsaid control means comprises: load cell means; at least one variableregulator in a first conduit for connecting a source of pneumaticpressure and said cell means; a pneumatic relay; a conduit connectingsaid relay to said first conduit; a second conduit connecting said relayto a valve and said valve to said actuator means; said cell means havinga rod for operation with said sensor means; nozzle means for directingpneumatic pressure against said sensor means and connected with saidrelay by a third conduit; and a fourth conduit interconnecting saidthird conduit and said second conduit and having a fixed orificetherein.
 4. A web tension control apparatus comprising sensor means fordetermining the tension on a moving web; tension producing means formodifying the tension on the web; said tension producing means includinga framework; a plurality of friction bars supported by said framework;at least one operating arm pivotally connected to each said frictionbar; an operating lever pivotally attached to each of said operatingarms; movable friction bars mounted on said operating arms; actuatormeans for activating said tension producing means; and control meansinterconnecting said actuator means and said sensor means, wherebymovement of said operating lever effects rotation of said operating armsand effects lesser or greater force against the web by said movablefriction bars and said fixed friction bars.
 5. A web tension controlapparatus comprising sensor means for determining the tension on amoving web; said sensor means including a framework having at least onestationary bar across which the web may pass; sensor arm means pivotallymounted to said framework; said sensor arm having a sensor portion; areflector plate mounted on said sensor portion; nozzle means fordirecting pneumatic pressure against said reflector plate; tensionproducing means for modifying the tension on the web; actuator means foractivating said tension producing means; and control meansinterconnecting said actuator means in said sensor means, whereby thetension on the web is sensed and pressure is automatically applied toestablish the desired tension in the web.
 6. The web tension controlapparatus of claim 5 wherein said control means comprises: load cellmeans; at least two variable regulators in a first conduit forconnecting a source of pneumatic pressure and said cell means; apneumatic relay; a conduit connecting said relay to said first conduitbetween said variable regulators; a second conduit connecting said relayto a valve and said valve to said actuator means; said cell means havinga rod for operation with said sensor means; nozzle means for directingpneumatic pressure against said sensor means and connected with saidrelay by a third conduit; and a fourth conduit interconnecting saidthird conduit and said second conduit and having a fixed orificetherein.
 7. The web tension control apparatus of claim 6 wherein saidtension producing means includes: a framework; a plurality of frictionbars supported by said framework; at least one operating arm pivotallyconnected to each said friction bar; an operating lever pivotallyattached to each of said operating arms; and movable friction barsmounted on said operating arms, whereby movement of said operating levereffects rotation of said operating arms and effects lesser or greaterforce against the web by said movable friction bars and said fixedfrIction bars.
 8. A web tension control apparatus comprising sensormeans for determining the tension on a moving web; tension producingmeans for modifying the tension on the web; actuator means foractivating said tension producing means; control means interconnectingsaid actuator means and said sensor means; said control means includingload cell means; at least one variable regulator in a first conduit forconnecting a source of pneumatic pressure and said load cell means; apneumatic relay; a conduit connecting said relay to said first conduit;a second conduit connecting said relay to a valve and said valve to saidactuator means; said cell means having a rod for operation with saidsensor means; nozzle means for directing pneumatic pressure against saidsensor means and connected with said relay by a third conduit; and afourth conduit interconnecting said third conduit and said secondconduit and having a fixed orifice therein, whereby the tension on theweb is sensed and pressure is automatically applied to establish thedesired tension in the web.
 9. The web tension control apparatus ofclaim 8 wherein said fourth conduit with said fixed orifice thereinconnects the third conduit connecting said nozzle means and said relayto said first conduit connecting said variable regulator with said cellmeans.